* {
  user-select: none;
  margin: 0;
  padding: 0;
  list-style: none;
}
#nav {
  line-height: 30px;
  background-color: #fff;
  border-bottom: 1px solid #f1f1f1;
}
#nav .container {
  width: 98%;
  margin: auto;
  display: flex;
  justify-content: space-between;
  padding: 10px 0px;
}
#nav .container > div > img {
  vertical-align: middle;
}
#nav .container > div:nth-child(2) {
  display: flex;
  justify-content: space-evenly;
  /* font-size: 16px; */
}
#nav .container > div:nth-child(2) > span {
  border-bottom: 2px solid transparent;
  cursor: pointer;
}
#nav .container > div:nth-child(2) > span.hover {
  color: #3a82f7;
  border-bottom: 2px solid #3a82f7;
  /* font-size: 16px; */
}

#nav .container > div:nth-child(3) {
  display: flex;
  justify-content: space-between;
  /* font-size: 16px; */
}
#nav .container > div:nth-child(3) > div {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid #c3c8d0;
  padding: 2px 5px;
  background-color: white;
  border-radius: 5px;
  transition: 0.5s;
  width: 70%;
  position: relative;
  overflow: hidden;
}
#nav .container > div:nth-child(3) > div > input {
  width: 80%;
  padding: 2px 2px;
  border: 0px;
  outline: 0;
}
#nav .container > div:nth-child(3) > div > button {
  width: 40px;
  position: absolute;
  right: 2px;
  height: 90%;
  background-color: #f2f3f5;
  border: 0;
  border-radius: 5px;
  background-image: url("https://lf3-cdn-tos.bytescm.com/obj/static/xitu_juejin_web/1e8ab9a22f0ddc36349f60b38900d0bd.svg");
  background-repeat: no-repeat;
  background-position: 50%;
}
#nav .container > div:nth-child(3) > div.cur {
  width: 100%;
  border: 1px solid #3a82f7;
}

#nav .container > div:nth-child(3) > button {
  border: 0;
  border-radius: 5px;
  background-color: #3a82f7;
  color: white;
  width: 25%;
  cursor: pointer;
}
#nav .container > div:last-child {
  display: flex;
  justify-content: center;
  align-items: center;
}
#nav .container > div:last-child > button {
  border: 1px solid #4a84ef;
  outline: 0;
  border-radius: 5px;
  background-color: #f5f8fe;
  color: #4a84ef;
  width: 50%;
  height: 100%;
  cursor: pointer;
}

/* 第二层 */
#nav_2{
  line-height: 30px;
  background-color: #fff;
  border-bottom: 1px solid #f1f1f1;
}
#nav_2 .container ul{
  width: 80%;
  margin: auto;
  display: flex;
  justify-content: flex-start;
  padding: 10px 0px;
  margin-left: 13%;
}
#nav_2 .container ul li{
  margin-left: 30px;
}